Metabolic response to enteral food in different phases of cancer cachexia in rats.

The resting energy expenditure (REE) and postprandial energy expenditure (PPEE) were measured using closed-circuit indirect calorimetry in Walker 256 carcinosarcoma-bearing rats. The results were compared to the appropriate controls. The PPEE measurements were performed after oral test feeding. At the beginning of the tumor growth, the REE and PPEE were similar in all groups. In the second week, the tumor-bearing rats showed increased REE and decreased PPEE. The tumor-bearing rats lost weight and became anorectic. After day 14, the REE rapidly dropped to very low values and the body weight continued to decrease. This study makes it possible to differentiate three phases of cancer cachexia: silent or preclinical, hypermetabolic and hypometabolic.